U.S. Pat. No. 802,106 which issued to Mattheson in 1905, U.S. Pat. No. 929,079 which issued to Cresse in 1909 and U.S. Pat. No. 1,839,156 which issued to Lumpkin in 1931 all disclose toilet seat warming apparatus. The method of warming the toilet seat common to all three patents is by circulating hot water through the toilet seat. The purpose of such apparatus, as described in the Cresse reference, was to shield the user from "the discomfort and shock commonly experienced by using toilet seats in cold weather".
Although construction methods and residential heating systems have vastly improved during the intervening years, the problem is still with us; albeit to a lesser degree.